Filter

Filter classes.

Note

Filters are used internally, and not recommended for use by Textual app developers.

Filters are used internally to process terminal output after it has been rendered. Currently this is used internally to convert the application to monochrome, when the NO_COLOR env var is set.

In the future, this system will be used to implement accessibility features.

NO_DIM module-attribute

NO_DIM = Style(dim=False)

A Style to set dim to False.

ANSIToTruecolor class

def __init__(self, terminal_theme):

Bases: LineFilter

Convert ANSI colors to their truecolor equivalents.

Parameters

Parameter	Default	Description
terminal_theme TerminalTheme	required	A rich terminal theme.

apply method

def apply(self, segments, background):

Transform a list of segments.

Parameters

Parameter	Default	Description
segments list[Segment]	required	A list of segments.
background Color	required	The background color.

Returns

Type	Description
list[Segment]	A new list of segments.

truecolor_style cached

def truecolor_style(self, style):

Replace system colors with truecolor equivalent.

Parameters

Parameter	Default	Description
style Style	required	Style to apply truecolor filter to.

Returns

Type	Description
Style	New style.

DimFilter class

def __init__(self, dim_factor=0.5):

Bases: LineFilter

Replace dim attributes with modified colors.

Parameters

Parameter	Default	Description
dim_factor float	0.5	The factor to dim by; 0 is 100% background (i.e. invisible), 1.0 is no change.

apply method

def apply(self, segments, background):

Transform a list of segments.

Parameters

Parameter	Default	Description
segments list[Segment]	required	A list of segments.
background Color	required	The background color.

Returns

Type	Description
list[Segment]	A new list of segments.

LineFilter class

Bases: ABC

Base class for a line filter.

apply abstractmethod

def apply(self, segments, background):

Transform a list of segments.

Parameters

Parameter	Default	Description
segments list[Segment]	required	A list of segments.
background Color	required	The background color.

Returns

Type	Description
list[Segment]	A new list of segments.

Monochrome class

Bases: LineFilter

Convert all colors to monochrome.

apply method

def apply(self, segments, background):

Transform a list of segments.

Parameters

Parameter	Default	Description
segments list[Segment]	required	A list of segments.
background Color	required	The background color.

Returns

Type	Description
list[Segment]	A new list of segments.

dim_color cached

def dim_color(background, color, factor):

Dim a color by blending towards the background

Parameters

Parameter	Default	Description
background RichColor	required	background color.
color RichColor	required	Foreground color.
factor float	required	Blend factor

Returns

Type	Description
RichColor	New dimmer color.

dim_style cached

def dim_style(style, background, factor):

Replace dim attribute with a dim color.

Parameters

Parameter	Default	Description
style Style	required	Style to dim.
factor float	required	Blend factor.

Returns

Type	Description
Style	New dimmed style.

monochrome_style cached

def monochrome_style(style):

Convert colors in a style to monochrome.

Parameters

Parameter	Default	Description
style Style	required	A Rich Style.

Returns

Type	Description
Style	A new Rich style.